GUIDE WHAT IS A DNS SERVER AND HOW TO SOLVE COMMON PROBLEMS 2020 -WAU

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What is a DNS server

What is a DNS server?. DNS is an acronym for Domain name system or Domain Name System, which is the method used by the Internet to translate easy to remember domain names like wpseguro.com instead of their IP 178.33.117.45 so that they are understandable by people and easier than if it is to remember numerical sequences, as is the case of IPs.

Every computer or device connected to the Internet needs an IP address and that it is unique so that it can be accessed from anywhere on the network.

Remembering IP numbers to access websites is a complex task that would greatly limit the amount that we could memorize, for this reason DNS helps us convert these numerical sequences into understandable names, and in most cases associated with the brand, entity, person or service they serve.

What are DNS


The DNS system was created in its beginnings to support the growth of communications through email in ARPANET, which was the predecessor network of the current Internet.

A decade after its creation and commissioning, the standards that shaped the current DNS protocol were established.

The WWW (World Wide Web) is based on the DNS protocol that Allows people-friendly navigation thanks to converting numbers to more understandable names and easy to remember.

That is, while we use more or less understandable names or those that are easy to enter in a browser, the servers prefer to convert those domain names to numerical addresses or IPs to reach the websites that we want to visit.

How DNS works


Each domain or subdomain has one or more authorized DNS servers that publish information about that domain and the name servers of any domain “below” it.

For example for the domain wpseguro.com the assigned DNS would be:

DNS mapping

The hierarchy of DNS servers matches the hierarchy of domains.

At the top of the hierarchy are the root name servers, which are the servers to query when searching for (resolving) a root name. top level domain (TLD).

Explained more graphically it would be more or less like this:

DNS resolution

If a server Primary DNS It usually fails that there is a Secondary DNS It operates independently and normally in a different network than the primary DNS to guarantee service redundancy.

That is why when a failure of the primary DNS server the secondary DNS server comes into action and responds to all requests from websites.

And as in any worthwhile contingency plan, many Hosting providers (as is the case with Websites Are Us) They also have a service of DNS failover (DNS failover) that is triggered by detecting that a server is not responding by propagating new DNS records to the entire system.

Check which DNS your domain points to


There are many existing services on the Internet to extract information from a domain, to know the data of the registrant and the registrar as well as the DNS pointed to by said domain and all this is obtained through a Whois.

Whois is a TCP protocol based on request / response used to query a database about the domain, its status and other more sensitive information (telephone, address) unless they have been hidden by services such as OwO (OvhWhoisObfuscateur from OVH).

There are several ways to find out:

  • Executing a whois from terminal (console).
  • Running dns.webempresa.io to check where each Registry points.
  • Consulting in DomainTools where the domain points.
  • Checking in your Client Area to Domains, My Domains, Nameservers tab.
  • Checking in DNS Propagation Checker that DNS returns the query.

Of course there are many more ways to check it but I am not going to list them in this article, with the mentioned ones it is enough to obtain this information.

From here, and knowing where the DNS of your domain points, if they do not point correctly the next thing is to know how to modify them.

If it is possible that a domain does not point all the DNS records to the same server, being able to separate these records by services (email, web, etc.) sending said traffic in both directions to a different server.

The records that make up a DNS are:

  • Top Level Domain (Root Domain)
  • CNAME or “Canonical Name”
  • Record A (Address Record)
  • MX Record (Mail Exchange)
  • PTR Record (Pointer Record)
  • NS Record (Name Server Record)
  • TXT record (Sender Policy Framework and DomainKeys)
  • SOA (Start of Authority Record)

For example, name servers (NS) are DNS servers that contain information about domains.

It is possible to have a website hosted on a different server from the same hosting provider or from another external one, simply pointing to the Record A that responds to the web and keep the mail pointing at MX Record on a different server.

Assign DNS to a domain


Normally, DNS can be assigned from your Client panel (in most providers). In the case of Websites Are Us clients, DNS can be assigned or modified from the Client Area, Domains, My Domains, tab Nameservers of the selected domain (click on the green “Active” button).

Change DNS

Once you make the change, the propagation of the DNS change is usually not immediate and you will have to wait a reasonable time for the change to take effect and your domain responds to these DNS and your website is visible.

The DNS propagation refers to the time it takes for DNS changes to transmit over the Internet.

As a general rule domains with TLD is they take the longest to activate or apply DNS changes.

Changes usually take up to 24 hours to propagate. In the case of .es domains, changes are processed by nic.es at 02:00 06:00 10:00 14:00 18:00 and 20:00 hours each day.

On the contrary, the top TLD domains like com, net or org usually spread within 4 hours after the DNS change, however in most cases in the minutes following the change they are usually available.

There can always be exceptions, so a dose of patience and calm is essential in these cases.

DNS errors how to fix them?


DNS is a vital point of the presence and accessibility of your website. Any user who tries to access your website through the Internet will not be able to do so if the DNS assigned to your domain does not work correctly.

If the DNS associated with your website fails, visitors who try to access the site will receive the error message of “Page not found” or “404 Page Not Found”.

It is not very common that errors occur with the DNS unless they are due to incorrect assignment, which is usually the most common scenario.

The usual message when a domain has no DNS record is:

DNS server is not responding.

DNS server is not responding

This type of errors can be caused by connection problems from the browser with which it is about reaching or solving a certain website.

It may be the case that the error of “DNS server not found” is due to a TCP / IP or DHCP protocol malfunction (common in fiber networks) or even that the cause is your Router or Modem device.

Other causes could be associated with infected computers by viruses or malware that make it difficult to connect to the Internet.

If for example this happens when trying to open a site with the Firefox browser, an option that can help to rule out the problem is to try to open the website from another browser, for example Google Chrome, Opera, Bing, Safari, etc.

Make sure you always use the most stable version of your commonly used browser to rule out that the problem is due to using an outdated or unsupported version.

Another solution that should always be tried in the face of this type of problem is cleaning or emptying the DNS cache (flush DNS), which sometimes becomes obsolete and needs to be emptied to renew it.

You can do it from a terminal or console on your computer by typing the command:

ipconfig /flushdns
sudo service network-manager restart

Or depending on the Linux distribution too:

sudo /etc/init.d/nscd restart
sudo killall -HUP mDNSResponder

In the case that the cause is the Router / Modem, try to turn it off first, wait a couple of minutes, turn it on again and after its complete activation verify that you can access the Internet and browse normally.

If after the restart of the Internet exit equipment the problem persists and yet through other means, from your mobile for example, if you have exit to the Internet and visualize the site that from the Router / Modem does not load, consider contacting your Internet (ISP) to resolve your issue with your device.

Also check that you can navigate connected to the Network Cable Router / Modem since it is very possible that if you do it regularly from your WiFi network, there is a saturation problem of the channel assigned to your SSID of the wireless network or that there is too much distance between your internet connection device and the wireless network point you are trying to connect from.

If you use a firewall or firewall, temporarily try disabling the shields that it uses, and then test Internet browsing.

You have done all these tests but the problem persists, do not worry, you can always assign other DNS to your output device to the Internet (Router / Modem) so that it uses, for example, those of Google:

Google DNS for IPv4 (the current standard):

Google DNS for IPv6 (new standard):

  • 2001: 4860: 4860 :: 8888
  • 2001: 4860: 4860 :: 8844

This type of assignments can be done from your Router or Modem device, if it allows it in its settings:

Google DNS mapping on the Router

Google’s DNS servers are much faster, and currently work with HTTPS offering security, as well as being free.

Conclusions


It is a proven fact that a large part of the incidents with domains recently purchased or transferred to a new provider are related to DNS (Nameservers).

Understanding how to detect and solve these problems is essential so that you can make use of your domains without errors.

The DNS resolution problems of a website are not always related to the server or the Internet service, in many of the usual cases the cache of your browser is the main cause of not displaying a certain website correctly.




By |2020-05-12T01:09:48+00:00May 12th, 2020|Administración del Hosting|